A review of 39 studies investigating the effect of exercise on cognition in older adults (50+) confirms that physical exercise does indeed improve cognitive function in the over 50s, regardless of their cognitive status. Aerobic exercise, resistance training, multicomponent training and tai chi, all had significant effects. However, exercise sessions needed to be at least 45 minutes and moderate intensity. Because aerobic exercise and resistance training had different effects (aerobic exercise helped overall cognition, while resistance training was particularly beneficial for executive function and working memory), it’s recommended that an exercise program include both.
 . Exercise interventions for cognitive function in adults older than 50: a systematic review with meta-analysis. Br J Sports Med [Internet]. 2017 :bjsports - 2016-096587. Available from: http://bjsm.bmj.com/content/early/2017/03/30/bjsports-2016-096587